Resveratrol is a substance in red wine. Experiments have shown that it allows mice to live up to 20-50 percent longer. Given in high doses, resveratrol blocks many of the ill effects of high-calorie diets. In experiments, the doses given to mice were larger than anyone can get by drinking red wine in moderation. The equivalent dose in a human would requires the person drink about 300 glasses per day. This is enough to destroy the liver and brain in fairly short order.

Resveratrol can be found in some dietary supplements. The major source in most supplements is from a plant grown in China with the interesting name, "Giant Knotweed". Although there is anecdotal evidence, thoroughly documented experiments have not been made that conclude that resveratrol from the Giant Knotweed has actual life extending effects on humans. Nevertheless, Sirtris Pharmaceuticals Inc, has begun testing resveratrol-based drugs on diabetes patients and for other uses.

How does resveratrol work? It seems to mimic a proven life extending process called calorie restriction (also known as CR). Calorie restriction is actually a very simple idea and involves reducing food intake by a third from the usual recommended amounts. This reduction in food intake has been shown (as early as the 1930s) to extend lifespan in animals (even higher order animals) by 30-40 percent. Nevertheless, this type of regimen is considered too rigorous to most people. They do not want to give up their lifestyle even for the prospect of extending their lifespan by several years.

Although there are other substances shown to have similar effects (metformin, for one) resveratrol is the first substance which has shown cross-species life extension. One nice thing about it is that it has been ingested safely, in large quantities by humans for thousands of years in the form of berries and especially grapes.

The benefits of resveratrol were discovered because studies at Harvard Medical School illustrated that resveratrol had benefits for yeast, extending the lifespan by as much as 70 percent. Speculation then arose that resveratrol might account for what is often called the "French Paradox". This is the observation that the French, in spite of high fat diets, and consumption of alcohol in the form of wine, have a longer than average lifespan.

According to an article in the November 2, 2006 issue of the Wall Street Journal resveratrol in the amounts available in most dietary supplements is considered safe. The high doses given to mice indicated that there might be problems associated with the liver, but even these were not pronounced considering the excessive amounts of resveratrol given to the mice. For humans to consume the amount of resveratrol given to the mice a human would have to take hundreds of resveratrol pills daily.

Besides the anti-aging effects, resveratrol also seemed to increase activity and endurance in aging mice. This might be because resveratrol stimulates an enzyme called SIRT1. This substance helps to spur the growth of new mitochondria in cells. (Mitochondria are the organelles of a cell that convert fuel to energy).

Whether or not this a promising new drug to help increase human longevity...only time can tell.